Adaptive support ventilation with and without end-tidal CO(2) closed loop control versus conventional ventilation.

MedLine Citation:

PMID:
23151992
Owner:
NLM
Status:
Publisher

Abstract/OtherAbstract:

PURPOSE: Our aim was to compare adaptive support ventilation with and without closed loop control by end tidal CO(2) (ASVCO(2), ASV) with pressure (PC) and volume control ventilation (VC) during simulated clinical scenarios [normal lungs (N), COPD, ARDS, brain injury (BI)]. METHODS: A lung model was used to simulate representative compliance (mL/cmH(2)O): resistance (cmH(2)O/L/s) combinations, 45:5 for N and BI, 60:7.7 for COPD, 15:7.7 and 35:7.7 for ARDS. Two levels of PEEP (cmH(2)O) were used for each scenario, 12/16 for ARDS, and 5/10 for others. The CO(2) productions of 2, 3, 4 and 5 mL/kg predicted body weight/min were simulated. Tidal volume was set to 6 mL/kg during VC and PC. Outcomes of interest were end tidal CO(2) (etCO(2)) and plateau pressure (P (Plat)). RESULTS: EtCO(2) levels in N and BI and COPD were similar for all modes. In ARDS, etCO(2) was higher in ASVCO(2) than in other modes (p < 0.001). Under all mechanical conditions ASVCO(2) revealed a narrower range of etCO(2). P (Plat) was similar for all modes in all scenarios but ARDS where P (Plat) in ASV and ASVCO(2) were lower than in VC (p = 0.001). When P (Plat) was ≥28 cmH(2)O, P (plat) in ASV and ASVCO(2) were lower than in VC and PC (p = 0.024). CONCLUSION: All modes performed similarly in most cases. Minor differences observed were in favor of the closed loop modes. Overall, ASVCO(2) maintained tighter CO(2) control. The ASVCO(2) had the greatest impact during ARDS allowing etCO(2) to increase and protecting against hypocapnia evident with other modes while ensuring lower P (plat) and tidal volumes.